Spray type concentrator



Aug. 29, 1961 R. c. JOHNSON SPRAY TYPE CONCENTRATOR 2 SheetsSheet- 1 Filed April 6, 1959 INVENTOR. 1?. C. JOl-lA/fiO/V W MA? 7 422 ATTORNEYS 1961 R. c. JOHNSON 2,998,059

SPRAY TYPE CONCENTRATOR Filed April 6, 1959 2 Sheets-Sheet 2 INVENTOR. I? C. J0H/v5aA/ ATTOENEYf States The present invention relates generally to improvements in the art of concentrating hygroscopic chemical solutions, and it relates more particularly to an improved system and apparatus for treating such solutions in order to remove excess moisture.

The principal object of this invention is to provide an improved device for concentrating moisture-laden antifreeze solutions, and an improved system for utilizing such a device in order to eliminate excessive frost formation on the cooling surfaces of refrigerating equipment.

While it has heretofore been proposed to employ spray type concentrators utilizing an air stream for the removal of excessive moisture from chemical solutions used as defrosting media in spray type industrial cooling units, these prior systems were all objectionable either because they were too complicated and difiicult to maintain in operating condition, or because they were operable at temperatures which resulted in the formation of objectionable scale on heat transfer units of such installations, or because they were otherwise relatively inefiicient.

It is therefore an important more specific object of the present invention to provide a simple but highly efiective spray type concentrator for hygroscopic chemical solutions and especially anti-freeze liquid such as glycol used extensively in spray type industrial cooling units.

Another important object of this invention is to provide an improved concentrator for moisture-laden antifreeze solutions in which the solution being treated is not permitted to contact heat-transfer surfaces which are subject to scale deposits.

A further important object of the invention is to provide an improved concentrating unit for frost-eliminating solutions utilized in refrigeration systems, which is efiectively operable at low temperatures.

Still another important object of this invention is to provide a highly efiicient glycol concentrator which is automatically operable to maintain such defrosting solution in proper condition for most effective cooperation with the cooling coils of air conditioning systems or the like.

These and other more specific objects and advantages of the invention will be apparent from the following detailed description.

A clear conception of the features constituting the present improvement, and of the construction and operation of a typical concentrator and system embodying the in vention, may be had by referring to the drawings accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

FIGURE 1 is a side view of a commercial spray type glycol concentration unit especially adapted to cooperate with refrigerated air conditioning systems or the like in order to defrost the cooling coil of such systems;

FIGURE 2 is a fragmentary top view of the unit shown in FIGURE 1 with portions broken away in order to reveal normally concealed structure; and

FIGURE 3 is a diagram of a typical air conditioning installation showing the manner of applying the improved spray type concentrator to such an installation.

While the invention has been shown and described herein as being advantageously applicable for the purpose of concentrating glycol used as a defrosting agent in spray atent type industrial unit coolers, it is not intended to restrict" communicating with the outlets 38.

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the use of the improved features to such installations; and it is also contemplated that specific terms employed herein be given the broadest possible interpretation consistent with the disclosure.

Referring to the drawings, the improved spray type concentrator shown comprises in general, a heater to which steam may be supplied from a main 4 through a stop valve 5, a solenoid valve 6 and a pressure regulating valve 7 into an upper header 9 from which it is dis tributed within a bank of heating coils 10 under pressure as indicated by a gauge 8, while the condensed steam collects in a lower header 11 and escapes through a steam trap 12 and past a check valve 13; a horizontally elongated housing 14 having its inlet end in open communication with the heating coils 10 and spanned by a mist eliminator 15 while its opposite outlet end is also spanned by another mist eliminator 17 and its medial portion forms a chamber having a plurality of spray nozzles 16 therein; :a centrifugal fan 19 confined within a casing 18 and driven by a motor 20 to withdraw :air through the heater and the spray chamber and to exhaust the air into the ambient atmosphere; a weak chemical solution supply pipe 21 which visibly delivers the solution to be conccntrated through a short relatively large pipe 23 into a sump 24 located below and in open communication with the spray chamber formed within the housing 14; a pump 26 having a suction pipe 25 in communication with the sump 2.4 while its discharge line 27 communicates with the spray nozzles 16, and a concentrated liquid discharge pipe 28 leading away from the sump 24.

The housing 14 may be formed of corrosion resistant sheet metal and is preferably provided with a cover plate 30, and the casing of the fan 19 should be provided with an inclined bottom 31 sloping toward the sump 24 in order to return any liquid which may be deposited thereon into this sump. The concentrator unit may be located at any convenient place outside of the refrigerated space and may either be suspended from an upright wall or other support upon angle irons 32 so that the outlet of the fan 19 is free from obstruction, or the unit may be suspended from an overhead support such as a ceiling in which case the fan outlet may be disposed horizontally within its casing 13. The heater may be supplied with steam from any suitable source through the main 4, and the air passing through this heater may also be derived from any desired source such as the room in which the heater is located, but the air discharge from the concentrator should be conducted outside in order to avoid recirculating the moist air. It is also important to note that the heating coils 10 are located in advance of the spray chamber and are not subjected to contact with the chemical solution being concentrated within the housing 14 thus positively preventing the formation of scale on these surfaces.

Since the improved spray type concentrator is adapted for advantageous use in the concentration of chemical solution such as glycol utilized as a defroster in refrigeration systems, a typical refrigerated system embodying such a concentrator is disclosed diagrarnatically in FIG- URE 3 of the drawings. In this cooling system, the air uni-ts served by the concentrator are usually located in the refrigerated space, and the refrigeration coil 35 which is to be defrosted is confined within the medial portion of a housing 36 having a lower side air inlet 37 and one or more conditioned air outlets 38 at its top. The interior of the housing 36 is provided with a glycol basin 39 beneath the air inlet 37 and with a series of spray nozzles 40 above the coil 35 and beneath several air blowers 41 The basin 39 is abundantly supplied with fresh glycol solution and some water may be added past a float valve 42 to compensate for over-concentration [by the ccncentretor, while a pump 43 has a suction line44 communicating with the basin 39 and a discharge line 45 connected with the spray nozzles 40. A heat exchanger 46 is interposed between the inlet pipe '47 leading into the basin 39, and a branch pipe 48 having a control valve49 therein is communicable through the heat exchanger 46 with weak glycol supply pipe 21 of the concentration unit. The passages within the heat exchanger 46 through which weak chemical solution is delivered to the concentrating unit, and through which concentrated solution is returned to the basin 39, are segregated from each other, and the quantity of weak solution delivered to the concentrating unit is controllable by adjusting the valve 49.

When one of the improved glycol concentrating units has been incorporated in a refrigerated air cooling installation such as illustrated in FIGURE 3, the operation is as follows, The air units are normally mounted within the space which is to be cooled, and whenever the cooling coil 35 is being supplied with refrigerant and the blowers 41 are operating, air from this space will be drawn into the housing 36 through the inlet 37 and will be cooled while flowing through the coil 3-5, being ultimatelydelivered through the outlets 38 to the space beingcooled, in a well-known manner. In order to prevent excessive frost from being deposited upon the coils 35 and thereby impairingthe eifectiveness thereof, thhe pump 43 should be operated to circulate anti-frost solution such as glycol from the basin 39 through the pipe lines 44, 45 and through the spray nozzles 40 onto the heat transfer surfaces of these coils 35.

However, during such spray defrosting operation, the hygroscopictglycol picks up considerable moisture from the air which is being cooled, and order to prevent excessive contamination onweakening of the chemical solution it is extremely desirable to utilize one or more concentrating units such as shown in FIGURES 1 and 2 operating in conjunctiontw-ith the air conditioning unit as in FIGURE 3. In order to do this, it is only necessary to open the valve 49 so as to cause the pump 43 to deliver regulated quantitiesof moisture-laden glycol solution through the branch pipe 48, heat exchanger 46 and concentrator supply pipe 21 into the sump 24, and to energize the heater while'operating the fan 19 and the pump 26. The amount of solution thus delivered into the sump 24 of the concentrating um't will be visible as this solution passes through the open gap between the adjacent ends of the supply pipe 21 and the enlarged 4 being circulated over the cooling coils 35. With the improved spray concentrator the temperature of the solution within the sump 24 depends upon the temperature of the air passing through the heating coils lil and upon the velocity of the air stream, and by controlling the steam supply and the speed of the fan 10 this solution temperature may be held relatively low. The improved concentrator can therefore be operated at relatively low temperature with the solution in the sump at approximately 100 F, and since scale does not readily form at temperatures below 120 F., no descaling of the heat exchanger 46 is required and the-heat transfer surface area may be reduced to a minimum.

pipe 23, and this amount may be readily determined by V the efiectiveness of the defrosting solution being sprayed uponthe coils through the nozzles of the cooling unit;

As the dry air which is drawn through the concentrating unit by the fan 19, flows through the steam heated coils 10 it is initially heated and delivered past the initial mist eliminator 15 into the concentrating zone. The Warm air stream is then subjected within this zone to multiple sprays of moisture-laden weak chemical solution being delivered by the pump 26 from the sump 24 through the nozzles 16 into the chamber within the medial portion of the housing 14, and the pre-heated air absorbs moisture from the chemical spray and thus concentrates the glycol which drops into the sump 24 and also concentrates and heats the liquid within this sump. The initial mist eliminator 15 merely serves to prevent moisture from reaching the heating coils 10, and the fan 19 draws the moisture-laden air through the final mist eliminator 17 wherein excess entrained liquid is removed and returned to the sump 24, and finally discharges the moisture-laden air-into the ambient atmosphere.

After the concentrating unit has been operating for a short period of time, the liquid within the sump 24 becomes heated and concentrated and this liquid is ultimately delivered via the outlet pipe 28 through the heat exchanger 46 and through the return pipe 47 into the basin 39 wherein it mixes with the chemical solution From the foregoing detailed description it should be apparentthat the present invention in fact provided an improved concentrating unit for vchemical solutions, which is simple and compact in construction, and highly effective in use, especially as applied to refrigerated air cooling systems. Because the air heating coils 10 are located in advance of the chemical spray chamber. and are separated from this chamber by the moisture eliminator 15, these coils 10 are not subjected to direct contact with the chemical, and the final moisture eliminator 17 located between the spray chamber and the fan 19 avoids possible loss of excessive quantities of chemical liquid with the exhaust air. The various controls and valves may be set to insure any desired degree of heating and concentration of the chemical solution necessary to insure proper defrosting of the cooling coils 35, without wasting valuable chemical, and the improved concentration units may be suspended from ceilings or walls or upon other supports with the aid of the angle irons 32. It should be understood that it is not desired to limit the present invention to the precise construction of the concentrating unit and its application to an air conditioning system herein shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art.

I claim:

1. In a concentrator for moisture-laden hygroscopic chemical solution, a casing forming a horizontally elongated open ended air duct, an air heater spanning one end of said duct, means at the other end of said duct for producing a iiow of air through said heater and the duct, a receptacle providing a chemical solution basin in the lower portion of said duct in open communication with the duct interior downstream of the heater with regard to the air flow, a mist eliminator spanning said duct between said heater and said basin, means for introducing moisture-laden chemical solution into said basin, spray nozzles directed into said duct on the downstream side of said chemical introducing means, and a pump for circulating moisture-laden chemical solution from said basin through said nozzles and the warm air stream heated by said heater and delivered through said moisture eliminator into said duct in proximity to said nozzles.

2. In a concentrator for moisture-laden hygroscopic chemical solution, a casing forming a horizontally elongated open ended air duct, an air heater spanning one end of said duct, means at the other end of said vduct for producing a ilow of air through said heater and the duct, a receptacle providing a chemical solution basin in the lower portion of said duct in open communication with the duct interior downstream of the heater with regard to the air flow, a mist eliminator spanning said duct between said heater and said basin, means for introduoing moisture-laden chemical solution into said basin, a second mist eliminator spanning said duct between said air flow producing means and said basin, spray nozzles directed into said duct between but in proximity to said mist eliminators, and a pump for circulating moistureladen chemical solution from said basin through said nozzles and the warm air stream heated by said heater while flowing over the basin.

3. In a concentrator for moisture-laden hygroscopic chemical solution, a casing forming a horizontally elongated open ended air duct, an air heater completely spanning one end of said duct, a fan at the opposite end of said duct for producing a flow of air through said heater and the duct, a receptacle providing a chemical solution basin in the lower portion of said duct in open communication with the duct interior downstream of the heater with regard to the air flow, a mist eliminator spanning said duct between said heater and said basin,

means for introducing regulated quantities of moistureladen chemical solution'into said basin downstream of said heater, spray nozzles directed into said duct on the downstream side of said heater and said chemical introduoing means, and a pump for circulating moistureladen chemical solution from said basin through said nozzles and the warm air stream heated by said heater.

References Cited in the file of this patent UNITED STATES PATENTS 2,162,158 Coey June 13, 1939 

